The expression “notebook” herein denotes a notebook computer, tablet PC, PDA (personal digital assistant), smart cellular phone (e.g., one capable of playing and displaying multimedia content), or other portable computer or computing system having a central processing unit (“CPU”).
The expression “auxiliary display subsystem” herein denotes a subsystem of a notebook that is configured to receive data (and typically cache the received data) from at least one other element of the notebook and to perform (while the notebook is in a standby state or other low-power state) at least one function that at least one other element of the notebook (external to the auxiliary display subsystem) could perform if the notebook were in a fully-powered normal operating mode. Examples of such functions include displaying cached video, still picture, or other image data (received from an element of the notebook external to the auxiliary display subsystem) or a processed version of such cached data on an auxiliary display, or causing such cached data or a processed version thereof to be displayed on all or part of the screen of the notebook's main display; playing back cached audio data (received from an element of the notebook external to the auxiliary display subsystem) or a processed version of such cached data; displaying system information (e.g., information regarding charge level of a battery of the notebook, or information regarding the notebook's state) on an auxiliary display or causing such system information to be displayed on all or part of the screen of the notebook's main display; and answering incoming telephone calls.
The expression “auxiliary display” herein denotes a display of the auxiliary display subsystem which is distinct from the main display of the notebook in which the auxiliary display subsystem is included. Some embodiments of an auxiliary display subsystem do not include an auxiliary display, and instead are coupled and configured to cause the display of data on all or part of the screen of the main display of the notebook including the auxiliary display subsystem (e.g., while the notebook is in a standby state or other low-power state).
The expression “secondary processor” of a notebook (having a central processing unit) shall be used herein to denote any processor of the notebook other than the notebook's CPU. Examples of secondary processors of conventional notebook computers are embedded controllers (e.g., embedded controllers that perform keyboard controller functions as well as other functions).
The acronym “SMB” herein denotes the conventional, two-wire bus known as the “System Management Bus.” The most recent version of the SMB is described in the System Management Bus (SMB) Specification, Version 2.0, published on Aug. 3, 2000, and available at http://www.smbus.org/specs.
The expression that a notebook is in a “low-power state” herein denotes that the notebook is operating in a state in which it consumes less power than if it were in a fully-powered, normal operating mode. Examples of low-power states are hibernation and standby states. Typically, a notebook has been booted up (and its central processing unit runs operating system software) when operating in a fully-powered normal operating state, but a notebook must perform a booting operation in order to undergo a transition from a low-power state to a fully-powered normal operating state.
It has been proposed that a notebook include an auxiliary display subsystem for caching data received from other elements of the notebook and displaying the cached data on an auxiliary display.
For example, US Patent Application 2004/0225901 (published on Nov. 11, 2004) discloses an auxiliary display system for use with a main computer (a personal computer or other computing device). The auxiliary display subsystem includes an auxiliary display, a memory, an auxiliary processor, and input devices, is operable while the main computer is in a standby state (e.g., to record voicemail, receive an incoming phone call, or play music), and is said to be capable of waking up the main computer while the main computer is in a standby state. The auxiliary display system can execute applications alone (without the main computer) or “in concert” with the main computer's “main processor.” In some implementations, the main computer has a main monitor, and the auxiliary display system is apparently configured to direct “display messages” to the auxiliary display or to forward them for display on the main monitor.
US Patent Application 2004/0222978 (published on Nov. 11, 2004) discloses a control and communications panel for use with a main computer. The control and communications panel can include an auxiliary display, an auxiliary processor, and controls, and can be operable (e.g., to perform telephone or other communication functions) while elements of the main computer are powered down.
US Patent Application 2004/0224638 (published Nov. 11, 2004) discloses a notebook with a built-in docking station for receiving a detachable media player having an auxiliary display and at least one data port (e.g., a USB port) for receiving image, audio, or other data from the notebook or sending data to the notebook. US Application 2004/0224638 suggests generally that communication between the media player and notebook could be one way or two way, and could implement a master/slave, server/client, peer to peer, or other protocol.
US Patent Application 2005/0076088 (published on Apr. 7, 2005) teaches a notebook (or other computer system) having a main display and a detachable module (having a processor, memory, auxiliary display, and input devices such as a fingerprint reader) mounted on the back of the notebook's main display. The detachable module can communicate with the notebook's main processor via a processor bus or communications link (e.g., to wake up the main processor). The detachable module can also perform functions such as displaying email, accessing contact and calendar information, and playing music files (apparently by accessing data previously cached, so as to be accessible by the detachable module, at a time when the notebook was fully powered up and booted up) when the notebook is in a “quiescent low power mode” without the need to boot up the notebook and load its operating system.